A comparison of somatic condition and testis mass in black-spectacled toad (Duttaphrynus melanostictus) between two populations at different altitudes

Abstract

Altitude, served as one common geographical gradient has been considered to have a major influence on the evolution of life-history traits, which leads to variation in temperature, food availability and duration of breeding season in amphibians. Here, we examined differences in somatic condition and testis mass of male Duttaphrynus melanostictus distributed in two altitudes (120 m and 1673 m above sea level) in Hunan and Yunnan Province, southwest China. We found that D. melanostictus displayed significant differences in body mass and relative testis mass between low- and high-altitude populations. Body mass and relative testis mass from the high-altitude population were larger than that of the low-altitude population in the species. We also found that testis mass increased with body mass and somatic condition. Furthermore, the somatic condition exhibited a significantly positive correlation with testis mass, indicating the condition-dependent testis mass in D. melanostictus.